2 Chainz Betting a FORTUNE on the ATL Falcons

2 Chainz is so confident in his ATL Falcons ... he's bettin' a FAT STACK on 'em!!

The Georgia rapper was out in Houston last night where he told us why he's throwing BIG MONEY on the Dirty Birds ... he even predicted the final score.

He's not the only rapper throwing around a fortune in Houston -- Migos told TMZ Sports they've got $300K IN CASH!!!